US6527810B2ExpiredUtilityA1

Bone substitutes

88
Assignee: WRIGHT MEDICAL TECH INCPriority: Oct 1, 1997Filed: Dec 21, 2000Granted: Mar 4, 2003
Est. expiryOct 1, 2017(expired)· nominal 20-yr term from priority
Inventors:James R. JohnsonJeffrey G. MarxWesley D. Johnson
A61F 2310/00017A61F 2310/00179A61L 2400/18A61L 27/56A61F 2/367A61F 2/36A61F 2310/00023A61F 2/30767A61F 2310/00131A61F 2002/2817A61F 2/389A61L 2430/02A61F 2310/00203A61F 2002/30884A61F 2310/00029A61F 2002/30968A61F 2/28A61F 2310/00293A61F 2310/00239A61L 27/425A61F 2002/30092A61L 27/427A61F 2210/0014
88
PatentIndex Score
147
Cited by
103
References
36
Claims

Abstract

A strong, porous article useful as a bone substitute material. The article comprises a continuous strong framework structure having struts defining interstices which interconnect throughout the bulk volume, and may have ceramic or osteoconductive material occupying at least a portion of the same bulk volume as the framework structure. Either as a coating on the strong framework struts or between the framework struts and the ceramic or osteoconductive-osteoinductive materials is a resilient material which serves to distribute stresses within the article.

Claims

exact text as granted — not AI-modified
What is claimed is:  
     
       1. A method for producing a strong, porous article useful as a bone substitute material comprising a continuous strong supportive sintered, load-bearing framework having struts defining a plurality of interconnecting interstices having 3—3 connectivity, and a resilient coating within said interstices and encasing said struts to provide residual strength to the struts and retain mechanical integrity of the article upon strut failure, wherein said resilient coating comprises a bioresorbable polymer and wherein said method comprises, 
       providing the continuous strong supportive sintered, load-bearing framework having struts defining a plurality of interconnecting interstices having 3—3 connectivity; and  
       contacting the framework with the bioresorbable polymer whereby said struts are encased with the bioresorbable polymer.  
     
     
       2. A method according to  claim 1 , wherein the sintered, load-bearing framework comprises a composite of zirconia and calcium phosphate. 
     
     
       3. A method according to  claim 1 , wherein the sintered, load-bearing framework comprises a ceramic. 
     
     
       4. A method according to  claim 3 , wherein the sintered, load-bearing framework comprises one or more of alumina and zirconia. 
     
     
       5. A method according to  claim 1 , wherein the sintered, load-bearing framework comprises a metal. 
     
     
       6. A method according to  claim 5 , wherein the sintered, load-bearing framework comprises stainless steel. 
     
     
       7. A method according to  claim 1 , wherein the bioresorbable polymer comprises a polymer selected from the group consisting of collagen, chitosan, chitin, poly(glycolic acid), poly (lactic acid), a copolymer of glycolic and lactic acid and mixtures thereof. 
     
     
       8. A method according to  claim 1 , wherein the bioresorbable polymer comprises a polymer selected from the group consisting of collagen, chitosan, chitin and mixtures thereof. 
     
     
       9. A method according to  claim 1 , wherein the step of providing the continuous strong supportive sintered, load-bearing framework further comprises: 
       providing a reticulated foam;  
       providing a slip of a ceramic or metal;  
       contacting the reticulated foam with the slip;  
       removing any excess slip;  
       drying to remove slip solvent; and  
       heating to a temperature sufficient to remove the reticulated foam and to sinter the framework.  
     
     
       10. A method according to  claim 1 , wherein the step of contacting the framework with the bioresorbable polymer further comprises coating the bioresorbable polymer on the struts of the framework. 
     
     
       11. A method according to  claim 10 , wherein the step of coating the bioresorbable polymer on the struts of the framework completely fills the interconnecting interstices. 
     
     
       12. A method according to  claim 11 , wherein the bioresorbable polymer includes a particulate osteoconductive material. 
     
     
       13. A method according to  claim 1 , wherein the interconnecting interstices have an opening ranging from 50 to 1000 μm. 
     
     
       14. A method according to  claim 1 , wherein the interconnecting interstices have an opening ranging from 200 to 600 μm. 
     
     
       15. A method of producing a strong, porous article useful as a bone substitute material comprising a continuous strong supportive sintered, load-bearing framework having struts defining a plurality of interconnecting interstices having 3—3 connectivity, a resilient coating within said interstices and encasing said struts to provide residual strength to the struts and retain mechanical integrity of the article upon strut failure, and an osteoconductive material contained within said interstices but separated from said struts by the resilient coating encasing said struts, wherein said method comprises, comprising: 
       providing a reticulated foam;  
       providing a slip of a ceramic or metal;  
       contacting the reticulated foam with the slip;  
       removing any excess slip;  
       drying to remove slip solvent; and  
       heating to a temperature sufficient to remove the reticulate foam and to sinter the framework to provide the continuous strong supportive sintered, load-bearing first framework having struts defining a plurality of interconnecting interstices;  
       providing within said interstices but spaced apart from said struts a solid osteoconductive material; and  
       providing a resilient interlayer between and at least partially separating said framework and said solid osteoconductive material.  
     
     
       16. A method as claimed in  claim 15 , wherein the step providing the osteoconductive material comprises: 
       providing a second rigid framework of an osteoconductive material contained within said interstices but spaced from said struts, and  
       the step of providing a resilient material comprises providing said resilient interlayer between and at least partially separating said first and second frameworks.  
     
     
       17. A method as claimed in  claim 16 , wherein the step of providing the osteoconductive material further comprises: 
       filling interstices of the sintered, load-bearing first framework with an osteoconductive material containing an organic binder; and  
       heating the osteoconductive material, whereby the osteoconductive material shrinks and forms an intervening space between the struts forming the first framework and the osteoconductive material second framework.  
     
     
       18. A method as claimed in  claim 17 , wherein the step of providing the osteoconductive material further comprises coating the struts of the first framework with a release agent before filling the interstices with the osteoconductive material. 
     
     
       19. A method as claimed in  claim 18 , wherein the release agent comprises a wax. 
     
     
       20. A method according to  claim 15 , wherein the sintered, load-bearing framework comprises a composite of zirconia and calcium phosphate. 
     
     
       21. A method according to  claim 15 , wherein the sintered, load-bearing framework comprises a ceramic. 
     
     
       22. A method according to  claim 21 , wherein the sintered, load-bearing framework comprises one or more of alumina and zirconia. 
     
     
       23. A method according to  claim 15 , wherein the bioresorbable polymer comprises a polymer selected from the group consisting of collagen, chistosan, chitin, poly(glycolic acid), poly (lactic acid), a copolymer of glycolic and lactic acid and mixtures thereof. 
     
     
       24. A method according to  claim 15 , wherein the interconnecting interstices have an opening ranging from 50 to 1000 μm. 
     
     
       25. A method according to  claim 15 , wherein the interconnecting interstices have an opening ranging from 200 to 600 μm. 
     
     
       26. A method of producing a strong, porous article useful as a bone substitute material comprising a continuous strong supportive sintered, load-bearing framework having struts defining a plurality of interconnecting interstices, an osteoconductive material contained within said interstices but separate from said struts, and a resilient material that completely fills the spaces between the struts and the osteoconductive material to provide residual strength to the struts and osteoconductive material retain mechanical integrity of the article upon strut failure, wherein the osteoconductive material is a continuous interconnected body, and wherein said method comprises: 
       providing a continuous strong supportive sintered load-bearing framework having struts defining a plurality of interconnecting interstices;  
       providing within said interstices but spaced from said struts, a solid osteoconductive material; and  
       providing a resilient interlayer between and at least partially separating said framework and said solid osteoconductive material.  
     
     
       27. A method according to  claim 26 , wherein the sintered, load-bearing framework comprises a composite of zirconia and calcium phosphate. 
     
     
       28. A method according to  claim 26 , wherein the sintered, load-bearing framework comprises a ceramic. 
     
     
       29. A method according to  claim 28 , wherein the sintered, load-bearing framework comprises one or more of alumina and zirconia. 
     
     
       30. A method according to  claim 26 , wherein the bioresorbable polymer comprises a polymer selected from the group consisting of collagen, chitosan, chitin, poly(glycolic acid), poly (lactic acid), a copolymer of glycolic and lactic acid and mixtures thereof. 
     
     
       31. A method according to  claim 26 , wherein the interconnecting interstices have an opening ranging from 50 to 1000 μm. 
     
     
       32. A method according to  claim 26 , wherein the interconnecting interstices have an opening ranging from 200 to 600 μm. 
     
     
       33. A method of producing a strong, porous article useful as a bone substitute material comprising a continuous strong supportive sintered, load-bearing ceramic framework having struts defining a plurality of interconnecting interstices having 3—3 connectivity wherein said method comprises: 
       providing a reticulated foam;  
       providing a slip of a ceramic or metal;  
       contacting the reticulated foam with the slip;  
       removing any excess slip;  
       drying to remove slip solvent; and  
       heating to a temperature sufficient to remove the reticulated foam and to sinter the framework.  
     
     
       34. A method according to  claim 33 , wherein the sintered, load-bearing ceramic framework comprises one or more of alumina, zirconia and calcium phosphate. 
     
     
       35. A strong, porous article useful as a bone substitute material comprising a continuous strong supportive sintered, load-bearing ceramic framework having struts defining a plurality of interconnecting interstices having 3—3 connectivity. 
     
     
       36. An article according to  claim 35 , wherein the sintered, load-bearing ceramic framework comprises one or more of alumina, zirconia and calcium phosphate.

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